Polyamide coated film element



eteetedMan 'by mesne assignments, to E. I, du Poixtdel} k Nemours &Company,- Wilmington, DeL, a con James EmoryjKirby,

, notation of Delaware,

No 'Kl plicationAugustl8ilil4l;

- seria No.

This invention relates to film comprising a synthetic linear polymer andhavinglat least one protective coating thereon composed of a polymer ofa long-chain monoaminomonocarboxylic acid. 1 A specific embodiment ofthe inventionrelates '5 to photographic elements comprisinga supportcomposed of a synthetic linear polymer; a pro=- 1 tectlve coating forsaid support composed of a long chain monoaminomonocarboxylic acidpolymer, and a light sensitive stratum. The inven- 10 tion furtherrelates to processes of fabricating or preparing such films andelements.

'The photographic industry has long'desired a stable, transparent,non-inflammable film. However, in spite of tremendous research incellulose and synthetic resin chemistry; cellulose nitrate has been usedalmost exclusively in professional cinematography; This is true in spiteof itsfire 1 hazard. For amateur films and. radiographic film whereininflammability is highly undesirable; 20 cellulose acetate and celluloseacetate/propionate are employed. Although these .orgamc acid esters ofcellulose are slow 'bui'n'ing', 'their ,physical properties are not allthat-isfdsired, -es'pe. cially from the standpoint of Qw'at'er istance,-flexibility, and strength. ,g x l Certain types of polyamideshavebeen'pro: posed for photographic film base, but have been found tobe somewhat water sensitive. This is particularly true ofpolyhexamethylene a'dip'amide and related' polyamides prepared from'diamines and dicarboxylic acids. Photographic fllms 'ma'de of suchpolyamides while they have exceptional:- strength, toughness, durabilityand iv fiexibility,'= are not entirely satisfactory for use, e."g.=in'pro fessional cinematography; where-water tolerance is very low. Thisistrue also of -the'most easily obtained amino acid type polyamidenamelmd' 6-aminocaproic acid polymerj l 1 The above disadvantages ofprior' 'art' i photofgraphic film base materials have been overcome andwater-resistant, commercially practical, photographic material andelements,. composed -.ofga synthetic linear po me .fi m-sup ot;.qbtainedlbm thehereinafter described invention.-

In a practical aspect hereof yaf self;supp oifiting film composed of asynthetic, linear; polymer.- d9; ficient in water-resistanceiis;firstmade; ;ior ex ample by e t udin ztha mo te polym sheet into a coolingatmqsphere orgintma quenching liquid such; as; w ater non-,solvent forthe polymer or it can be formed into a sheet by rolling be tween metalrolls. Film can also be madefrom 5s solutions of the; polymer-glby-evapor tive oi eoa lative methods. A;$01ut ion v resistantimonoaminocarboxyl port or filmbasethus obtained bj for'mjacoaa, ing orlayer. The aminocarboxylic acid ipolymer layer can be, depositeddirectly he Tsurfaceor" surfaces;0, ;..the" base. or support .oronla'jsub stratum or subbing layer which'gis directly im-fj.

posed on the base. pneormore layers-of said aminocarboxylic acid,polymersjican bev deposited'..

The 1 type of solvent used inftlie coating sclu tion may vary quitewidely. InJgenera'l, however,

- a solvent is chosenwhich does'notdiss'olve the film support.Theparti'cular solvent chosen 'de- I pends somewhat on. the] long,,chainaminocar boxylic acid polymer? andithe thicli n'essflofj thecoating desired; In general; dilute solutions containing from Ito10fp'art'sof the polymer in: 99"" to 90 parts'offsolvent-are"mostpracticah Bela" 1 tively volatile solventsi; e.boiling below 100 C.,"

v are preferred.lPracticals ventsfincludealiphatic:

alcohols, aliphatic altdiioi ardmaaej hydrocarbon,

mixtures. chlorinated hydrocarbon alcohol mix: tures, or combinationsof. these, ,in'any de'sired" -manner. n

is allowed Artereoatmg, the cam v H r th'e solvent;

set or harden or "is dried by removin .Ihis may conveniently' be doiieby allowing the solvent. to evaporate, at moderate temperatures,

e. g. 50 C.-,; z t-normal or reduced pre suie. l'I 'l-iev drying processcan expedited he passage,

of a. m, T v s s q l sm d i m u' h?asj. .airi;l

subject. th fi m" 3 be one or moreoperatigins desi' physicalpropertiesof th cosity of kling drops 253, and 2,130,948. The preferred filmsupports cording to to the further aspect of the invention,

the film supports may be subbed or provided with a substratum coating inorder to anchor other layers e. g. colloid layers to the support.Especially suitable subbing or coating solutions are described inMiddleton, McQueen and Hill application, Serial No. 360,202, filedOctober 'I, 1940. Other known"subbing solutions, however, can beemployed if desired.

If the composite film, i. e. the synthetic linear polymer filmcoatedwith long chain aminocarboxylic acid polymer, is to be used as aphotographic film base, an outer surface which may be the layer composedof a long chain aminocarboxylic acidpolymer or the surface or subbedsurface of the film base is then coated with a photographic colloidlayer. Various types of colloid materials may be deposited to formlayers having photographic characteristics. Colloids containing filterdyes, anti-halation dyes or pigments, light sensitive materials, dyeintermediates or color formers, sensitizing dyes or mixtures of one ormore of these as is known to the art, may be coated on the base or alayer imposed thereon. One or more of such layers may be deposited orplaced on each side of the protected film base.

The invention will be exemplified but is not intended to be limited bythe following examples wherein the parts stated are parts by weight.

EXAMPLE -1 Ten parts of a polymer prepared from 12- aminostearic acid ofintrinsic viscosity (as defined in U. S. Patent 2,216,735) 0.81, andsoftening point 116 C. is dissolved in a mixture of 139 partstrichloroethylene and 51 parts ethyl alcohol. This solution is methyleneadlpamide having an intrinsic vis- 0.9 and a melting point of 263 C.under oxygen-free conditions and the excess removed. After drying at 65C., the film is observed to be clear, transparentand very tough. Onflexing or tearing,

definite increase in water-repellency over the uncoated film can benoted.

Another film of polyhexamethylene adlpamide coated similarly to thefirst, but on both sides shows the same properties of water-repellency,

strength and good adhesion. The decrease in.

water absorption of these two films over uncoated polyhexamethyleneadlpamide is shown in the following table, whereinthe timesindicateddenote the duration of the period of immersion in water. In obtainingthese data the size of the immersed'sample was approximately four squarecentimeters, the total thickness 0.0063 inch and the thickness of thefilm before coating 0.005 inch.

Table I Gain in weight Film 1 15 minutes One hour Per cent Per centPolyhexamethylene adlpamide 3. 0 8. 3 Polybexamethylene adlpamide coatedon one side '1. 8 7. l Polyhexametbylene adlpamide coated on both sides0. 9 3. 4

This striking increase in resistance to water is particularly remarkablewith such small samples where edge seepage accounts for a largeproportion of the take-up.

ExAMPLa II A film of epsilon-aminocaproic acid polymer,

. prepared from caprolactam is coated with an interploymer prepared from45 parts of hexamethylene diammonium adipate and 55 parts no separationbetween the coating and the base can be observed; On sprinof water onthe coated surface a trichloroethylene and 54 parts ethanol. Afterdrying at C., a smooth, clear, transparent film is obtained. Theincrease in weight of a dry sample of this film after 50-minutesimmersion in water is 3.9%, while that of an uncoated control film ofepsilon-aminocaproic acid polymer at the end of the same time is 7.4%.

EXAMPLE III A film of polyhexamethylene carbamate (M. P. 150 C.)prepared from hexamethylene glycol and hexamethylene diisocyanate, iscoated with a polymer prepared from a mixture of 9- and lo-aminostearicacids by passing the film rapidly through a solution of 5 parts .of thelong chain amino acid polymer in 65 parts chloroform and 30 partsmethanol and drying at 65 C. r A tough, flexible; transparent, film ofimproved water-resistance results.

EXAMPLE IV is dried at 80 C. in a current of warm dry air.-

A tough, elastic, transparent product of improved water-resistanceresults.

EXAMPLE V A double coated film base prepared in accordance with theprocedure set forth in Example I is then subcoated with a mixturecontaining 1.8% .gelatin, 14.2% cresol, 30% methyl alcohol, and waterand acetone in suitable proportions. After drying, the sub film base iscoated with a panchromatized silver-gelatino bromide emulsion layer ofmilligrams coating weight per square decimeter. After exposure anddevelopment the emulsion layer is found to be firmly anchored to thefilm support even 'under wet conditions.

' Satisfactory anchorage; of the enijilsio li tot is represent met; a $2acids have A double coated flimg ga semreparedg ance with the procedggeseti Exarnp e is coated on each side mith in-Q 189 solution comprising amixture of 2 parts 01: e; 1101 and fiflp otc i-ice lu -eeetetei if!subcoat comprising;

lem ne s a. n9 Y ivi des s; m q it ns ee eie le min acmer tnea oveitypeacne;

eferred to 'as"interpolyaihids,

ilarly protectedjgyr appiying a iayerijoi-a polymer WWW Usu ll Prep re mre. 9??" of a ethei im eeeminq qno arb ylia. ac In d917, 9mg to the basein the manners hereindescribed. v t .v W Sultablebase irraterials aredescribed lathe {UL Sf base with use of i w Ye e =9e ee patentsgcitedahoveaudio-need is seen'for llsth w a polymer'f-omtmg' reactants fing them in thisspec'ificatiom, The poiyalnides wh the fie y m f dlshouldfconT described- 1h U. is. 2,216,735, page 2, column 2, mm1east25.% of l e w n e lines 6. to pa e 3,O1!.1Ii1i1.1 line 32,arepreferred v The Q flpqlyamlde 5' used e ine u e base materials.The'polymers. of .long chain 25 ne the el m r h b ne le yarninocarbcxyllclacidslused in. the 'present ln f m/ h above mentioned W1 aQidS 1 vention' are prepared from avmonoam inomono- 9 is m m fie scarboxyiic acid or; an amide-forming derivative 7 withother l m d m e tab t thereof havin gfa chaint'containing at least nine e e Q- p mobtaned: rnm n m carbon atoms, the amino-groupinsaid acid or 3 of e vamino acids wlth other m derivative carrying at least one hydrogen atomm n re vt e r r mixture 9 3 19 n and being attached to; a;carbon atomwhich is d asic 3191117 'Ihe' oly rs thus ro te n d'c separated from the;carboxyl group by at least l ah of amlde glioups a an fi four atoms.The term long chain monoaminov a monocarboxylic acid polymer? includesalso in- 35 l' 'l e er d 3 ye d sa i tgrpolymrs f. u w1 h ip y ysis'with hydrochlonc acid the polyam deswof part of the mainflchain of atomsand my; there-- forming reactantsinwhich the amount of said thi hi n i nYield the hydroQhlorid 'i Q t acids constitutes at least 25 hey 1 yygminqaicidhusedim e preparation s lr s m e i es U e u olymesmm a Mam;551k.- 0 9$. l d in l mer therifireparafionwe sbl ition at least,"because l i ,,.,y in

include alsoit s amideh I Ql li l lfiqi j the phenoljasthei nhydrieaester-1 mid Suchpmduets as. well' eiq i bet p asti'c'izisqirothermodifying agents e f n "Ani esjpec ially u seful classofarnirioca'i bcitylic 11 5 I Midi eye-mash 'stQ fii 1 aa e. ilzba tameeeeemtea lilf iitwngw e m- 1 ucli asbea of cases. The particular solventchosen, of course, varies considerably with the particular linearpolymer base and the particular long chain amino acid polymer chosen.The temperatures of the coating bath may also vary i widely, dependingupon the solvent employed and poured on and leveled by means of a doctorknife,

or applied by passage of the film base through the solution. It has beenfound that drying the film at elevated temperatures is particularlyconducive to producing clear transparent haze-free films, although inmany cases this operation is not necessary. Suitable drying temperatureslie within the range 30-150 C.

The high water resistance of the films of this invention, together withtheir clear transparent nature, makes them of value as a wrappingtissue, particularly in the packaging of materials which are desired tobe exhibited to view and which are subject to deterioration by gain orloss of moisture. These tissues present the remarkable strength,toughness, and pliability common to linear polymers in general with thehigh degree of surface slippage and water resistance contributed by thelong chain amino acid polymer.

A further advantage of the films of the present invention is theirstability upon storage, even at elevated temperatures. Under suchconditions the products show remarkable resistance to heatembrittlement.

While a preferred embodiment of the invention is concerned with adheringradiation sensitive silver halide layers, to the moisture-proofed orprotected synthetic linear polymer film bases, it is not limited to thataspect. n the contrary,

.(1) heat sensitive layers of silver or mercurous oxalate in gelatin,(2) light sensitive diazo dye layers, (3) fulgides, i. e. anhydrides offulgenic acids which are particularly sensitive to ultravioletradiations, (4) antihalation layers, (5) light screening layers, (6)bichromated hydrophillic colloids, (7) dye component layers utilizingorganic reversible colloid binding agents, and immobile color formers,etc. may be attached to the composite film base hereof, including asuitably subbed composite film base, in a manner similar to thatdescribed in Examples V and VL It is to be observed that aphotosensitive material can be applied to the composite film base ofthis invention without the use of any special adhesive, such as gelatin.The photosensitive material can be incorporated in the amino acidpolymer itself or can be applied to the amino acid layer while it isrendered adhesive by heat or a solvent.

when the coated film is to be used as a photographic film base, thelight-sensitive layer'or layers applied can vary somewhat in theirchemical constitution and are preferably silver halides. They can besimple or mixed and have various types of binding agents. As examples ofpractical coatings, mention is made of silver chloride, silver bromide,silver chloro-bromide, and silver iodo-bromide gelatin emulsions.Various emulsion components such as sensitizing dyes descnsitizing dyes,fog inhibitors, emulsion stabilizers, immobile color formers, lightscreening dyes and pigments may be present in such layers. It has beenfound that these layers adhere fairly well to the composite film base.However, the outer polyamide coating can advantageously be subbed beforeadditional colloid layersare applied.

The novel film elements of this invention which contain theabove-described substrata are not restricted to any one type or for anyone purpose.

On thecontrary, cut or roll film for still or motion picture photographyor radiographic purposes, perforated positive and negative motionpicture film stock, including film having asingle sensitive layer forblack and white pictures or film having "a plurality of sensitive layersfor color pictures or transparencies; stripping films, etc., arecomprehended.

The film base hereof is especially useful for photographic film elementswhere non-shrinking characteristics are highly desired. Such films areuseful in various types of lithographic processes including wide rangelithographic processes, map making, and processes for making layoutdesign plans and templates on sensitized aluminum foil. In the lastmentioned type lithographic film elements are used for copying theoriginal drawing and projecting the negative made on the lithographicfilm onto a sensitized.

aluminum base. Film of this type must have a limited amount ofdistortion from water-adsorption and these requirements are met by theelements of this invention.

The photographic film made from the polyamide coated film of thisinvention is slow buming and may be used without the fire hazardattached to the present use of. cellulose nitrate films. Particularlyadvantageous in the photograhic field is the high degree of waterresistance which the films manifest. This results in extremely smalldeformation during processing even when the films are left for longperiods in running water. This resistance to aqueous solutions alsoprevents curling of the films upon drying, an important property inincreasing the life of professional and amateur movie films which mustlie fiat to go through the projector satisfactorily. 0f additionaladvantage in the case of cinematographic film is the excellent surfaceslippage of the self-supporting films of the present invention. Thismanifests itself in a lack of excessive friction in passage throughprojector or printer gates.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that the invention is not to be limited except as defined inthe appended claims.

I claim: I

1. A self-supporting film element comprising a film base composedessentially of polyhexamethylene adipamide having at least one surfacethereof protected with at least one layer composed essentially of al2-aminostearic acid polymer.-

2. A self-supporting film water sensitive film base composed essentiallyof a fusible water insoluble synthetic linear polycarbonamide having anintrinsic viscosity of at p lymer.

JAMES EMORY KIIBBY.

element comprising a I

